Sand-blast machine.



F. P. BOLAND.

SAND BLAST MACHINE.

APPLICATION FILED JUNE 11, 1908.

Patented M2122, 1909.

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' B NVEN TIIIR: Tvmx Bohxnka with a is supplied the. sand or abrading material employed'in the machine. 'The rear side of 1 ing guard or protector b dispose with respect to the usual hand-holes d To all tvkom it may concern: v

. several parts being'represented in the normal my improvements: The head or body portion of the machine is sup orted by legs Z and munication with the upwardly inc ined holv in' a novel mer at or below the hopper -rnnf snares err-aw rrron FRANCIS BOLAND, OF PROVIDENCE, RHODE ISLAND.

shun-sneer MACHINE.

Be it known that I, ,FRANoIs P. BoLAND, a citizen of the-United States of America, and a resident of Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements irrSand-Blast Machines, of which the following is a'specification.

This invention relates to improvements in sand-blast machines, so-called, and it consists in the novel construction and combination of parts arranged to produce a continuous blast or working efiect with a greater de' cc of efficiency than is obtainable in machines of this class heretofore devised.

The ,improved'machine is simple'in construction and comparativelyinexpensive to manufacture, all es more fully hereinafter set forth and claimedsf -In the accompanying sheet of drawings, F1 ure 1 represented "side elevation,in part'a section, of a sand-blast machine embodymg my improvements, and Fig. 2'is a vertical longitudinal sectional view, in enlarged scale, taken through the center of the auxiliary sand holder and the air-blast connection; the

operative'lposition or relation. r The fol owing is amore detailed dscrip tion of a sand-blast, machine provided with provided with what may e termed the operating or working chamber '0 having transparent sides. The front side is provided swinging door 0 capable of being opened and closed. A perforated horizontal partition or work-supporting plate i separates thechamber proper fromthe main hop er or sand reservoir e beneath, from which latter the chamber; a is in continuous Q on com low extension f which terminates at the top 'in the enlarged exhaust outlet 9 communicating with the outer air. The 'topportion of the head member may have a p amidal forin, as indicated at a. Thesaid ont side is also provided with an outwardl extendbelow said door 0.

The presentinvention resides more pa b ast Specification of Letters Patent. Application filed June 11, not. serial No. esters.

and located ticularly in combining. the sand and air Patented March 2, 1909.

and. conducting the thus acted u on sand upwardly therefrom unobstructed y to the discharge-nozzle of.

A verticall arranged small cylindrical, auxiliary hol er s havin a chamberr is as drawn located below the opper and being in direct communication therewith via pipe m and the interposed valve or cook m the latter being employed for controlling the flow of sand from the hopper. The ower portion s of the said member s is'beveled and provided with a fitting or end it tapped to receive the tubular end of an elbow member t the latter in turn arranged to receive air underpressure from a suitable air-supply or blower via ipe t. The said member t is reduced in iameter to form a nozzle t the same extendin upwardly through the bottom of the ho er s a short distance. A circulating-pi e it passes downwardly through thetmova le to or cover 3 of the holder s and is positione so as to form at the bottom an annular space t between the former and said nozzle t and at the same time having the part of the pipe adjacent the .latter provided with perforations p. The

circulating-pipe passes upwardly throu' h a lateral recess f of said extension f and is cut L to a'comparatively lar e semi-circular form and terminates in the ownwardly open discharge-nozzle of. As thus devised and shown the circulating-pipe is unobstructed throughout its entire length, except at the usual discharge-nozzle, since no branch pipes and valves are connected with or joined to it, the result being that a greater degree of efiiciency and economy are attained.

In operation air under suitable force or pressure flows via pipe t and bore t of the elow or fitting 1! directly into the lower end portion of the circulating-pipe a and prouces an upward draft or current in the latter, the'result being tosuck the sand (flowing by gravity from the open hopper into the chamber 7 of the holder 8) through the apertures or perforations p into the annular space i the thus combined or associated air and sand pass upwardly and uuobstructedly through pipe at a and are discharged from the main nozzle u;-the force of the thus eglected sand being employed for abrading t e surfaces of articles of metal or other material heldthereunder.

.. per into the said annular space, and alsoto then force it upwardly therefrom in the tate the sand preparatory to or in conjunction with the action of the air-blast proper located-at or near the discharge-nozzle of the circulating or feed-pipe and forming a mixing chamber at that point. As thus devised the loosened sand is-drawn upwardly into thesaid chamber by the main\ air-blast introduced into the latter.

In my'invention the lower end of the feed pipe 11, is continuously open and extends a short distance below the continuously open discharge-end of the air-nozzle 15, thus producing an annular space which is kept filled with the sand,"the latter, however, not overflowing into the air-nozzle as in the case of a fluid, If desired means may beemployed for regulating the flow of sand from the hopmeans, as a cock g, forfcontrolling' the volume of air-supply issuing from the airnozzle.

I do not desire to limit my invention to the precise or exact construction and arrangement of parts asshown and described herein "as changes or modifications of the device may be made therein without "departing from the spirit. or scope of the invention.

'1 claim as my invention and desire to secure by United States Letters Patent,

In a sand-blast machine, the combination with the casing or body portion provided with a workingchamber, a main reservoir for sand located below and being in open .com-

munication with said chamber, andan auxiliary reservoir into which sand may flow from the main reservoir by gravity, of an open air-blast inlet-nozzle extending upwardly a short distance through the bottom of said auxiliary reservoir, a main circulating-pipe having its lower portion perforated and surrounding the sai an annular space therebetween into which space the sand passes by gravity action, and having the circulating-pipe extending upwardl through the auxiliary. reservoir and provi ed with a return bend terminating in a nozzle arranged to discharge mingled sand and air into said working chamber by the action of the air-blast issuing from said inletnozzle, substantially as described.

HENRY P; STONE.

inlet-nozzleso as to form '60 Signed at Providence, R. I. this 9thday 

